Refrigerating apparatus



Sept. 7, 1943.. H. J. SCULLEN 2,329,141

REFRIGERATING APPARATUS Filed Aug. 25, 1940 INVENTOR. 40 1/. CULLN ATTORNEY.

Patented Sept. 7, 1943 REFRIGERATIN G APPARATUS a Hugh J. Scullen, Detroit, Mich assignor to Nash-Kelvinator Corporation, Detroit, Mich., a corporation of Maryland 7 Application August 23, 1e40, Serial No.'353,943

,6 Claims. (of. 62-116) This invention relates to refrigerating apparatus, and more particularly to refrigerating apparatus of the multiple temperature typefw One of the objects of my invention is to provide a refrigerating apparatus which includes a primary refrigerating system having an evaporator providedwith an accumulator at its outlet and a secondary refrigerating system arranged with the condensing portion thereof in heat exchange relation with the accumulator of the primary refrigerant evaporator.

Another object of my invention is to control the temperature in the secondary refrigerating system by connecting the condensing portion thereof in heat exchange relation with the liquid refrigerant accumulator of a primary refrigerating system and by controlling the amount of liquid refrigerant which is permitted to flow into such accumulator.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanyratus shown in Fig. 1 showing the ends of the accumulator partially broken away.

Referring to the drawing, the numeral designates, in general, a primary refrigerant evaporating element or evaporator which has a liquid refrigerant accumulator 2| connected with its outlet. Liquid refrigerant is supplied to the evaporating element by a condensing element designated in general 24. The condensing element includes motor-compressor unit and condenser 28. The motor-compressor unit 26 withdraws gaseous refrigerant from the accumulator 2| through vapor return conduit 30. The compressor compresses the refrigerant and delivers it to the condenser 28 wherein it is liquified and from which it is delivered to the evaporator 20 under the control of a small diameter or capillary tube 34. Preferably the vapor return conduit 30 and the small diameter tube 34 are secured together in thermal heat exchange relation so that the liquid refrigerant flowing through the conduit 34 is pre-cooled before entering the evaporator 20. As will be noted in Fig. 2, the outlet end of the evaporator 20 enters the lower portion of the accumulator 2| while the vapor return conduit 30 is connected to the upper portion of the accumulator 2|. Preferably, the evaporator 2|), condenser 28, motor-compressor unit 26 and the length and internal diameter of tube 34 are so computed that very little liquid enters the accumulator 2| during normal operation of the refrigerating system. Consequently only gas exists in the upper portion of the accumulator and only gas returns to the compressor through the return conduit 30. In view of the fact that only a small amount of liquid enters the accumulator 2|, such liquid will evaporate and do some cooling, and when only a small amount of liquid enters the accumulator the amount of cooling will be determined by the amount of evaporation and liquid in the accumulator. Consequently the accumulator will not be at as low a temperature as the evaporator 20. Preferably, the evaporator 20 is formed in the shape of a serpentine coil and is utilized for freezing substances such as ice cubes in the well known manner. With the accumulator operating at somewhat higher temperature, I have found that I can associate the condensing portion of a secondary refrigerating system in heat exchange relation with the accumulator and operate it at a higher temperature than the temperaure of the primary refrigerating system.

The secondary refrigerating system as herein shown includes a condensing portion M] which is secured to a semi-cylindrical clamping portion 42. The portion 42 conforms-to the curvature of the accumulator 2| and is clamped in heat exchange .40 is associated a secondary refrigerant evaporating portion 5|). Preferably, the secondary system is formed of one continuous conduit providing open communication throughout the condensing and evaporating portions so that when liquid refrigerant evaporates in the evaporating portion 5|) it will flow from the upper portion thereof through a vertical leg 52 to the condensing portion 40 wherein the gaseous refrigerant will be condensed by the refrigerating effect of the accumulator 2| and flow through a vertical return leg 54 into the lower portion of the evaporating portion 50.

It will therefore be noted that I have provided a simple arrangement for the transfer of heat from primary and secondary refrigerating systems and have arranged the condensing portion of the secondary system so that it is not in thermal heat exchange relation with any portion of the primary refrigerating system which is called upon to do useful work. Instead, I have associated the secondary condensing portion in heat exchange relation with a liquid refrigerant accumulator and have arranged the primary refrigerating system in such manner that only a small quantity of liquid refrigerant enters the accumulator so that the refrigerating effect of the accumulator is such that'the secondary refrigerating system operates at a higher temperature than the primary refrigerating system.

Although only a preferred form of the invention has been illustrated, and that form described in detail, it will be apparent to those skilled in the art thatvarious modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. Refrigerating apparatus comprising a primary refrigerating system including an evaporator having a liquid refrigerant accumulator, a clamping member having a surface adapted to conform to the outer surface of said accumulator and being removably secured to said accumulator and a secondary refrigerating system including a condenser secured to said clamping member for thermal association with said accumulator and a secondary evaporator connected to said condenser.

2. Refrigerating apparatus comprising a refrigerant evaporating portion, a tank connected to the outlet of the evaporating portion for receiving the overflow liquid therefrom, a clamping member having a surface adapted to conform to the outer surface of said tank and being removably secured to said tank, an independent refrigerating system including a condenser secured to said clamping member for thermal association with said tank and an evaporator connected with said condenser.

3. Refrigerating apparatus comprising a primary refrigerating system including a sinuous non-flooded refrigerant evaporating conduit having a refrigerant accumulator at the outlet thereof, said primary system being provided with such a charge of refrigerant that said accumulator receives surplus liquid refrigerant in limited quantities only from said evaporating conduit during the on-cycle' of the primary system wherebysaid accumulator is maintained at a higher temperature than said primary evaporating conduit, and a secondary refrigerating system including a condenser secured in thermal contact with said accumulator and a secondary evaporator connected to said condenser.

4. Refrigerating apparatus comprising a pri-- mary refrigerating system including a sinuous refrigerant evaporating conduit having a refrigerant accumulator at the outlet of said conduit, said accumulator being maintained at a higher temperature than said evaporating conduit by limiting the quantity of unvaporized refrigerant conducted thereto, a secondary refrigcrating system including a condenser and an evaporator connected to said condenser, and a metallic clamping member for securing said condenser and said accumulator in heat exchange relation.

5. Refrigerating apparatus comprising a primary refrigerating systemincluding a, liquid refrigerant evaporator, a clamping memebr having a surface adapted to conform to a portion of said evaporator and being removably secured to said portion, and a secondary refrigerating system including a condenser directly secured to said clamping member for limited thermal association with said evaporator and a secondary evaporator connected to said condenser, said clamping member being arranged to lie between said first named evaporator and said condenser.

6. Refrigerating apparatus comprising a primary refrigerating system including an evaporator having a liquid refrigerant accumulator, said primary system being provided with such a charge of refrigerant that said accumulator re: ceives surplus liquid refrigerant in limited quantities only from said evaporator during the oncycle of the primary system whereby said accumulator is maintained at a higher temperature than said primary evaporator, a clamping member having a surface adapted to conform to the outer surface of said accumulator and being re movably secured to said accumulator, and a secondary refrigerating system including a condenser directly secured to said clamping member for limited thermal association with said accumulator and a secondary evaporator connected to said condenser, said clamping member being arranged to lie between said accumulator and said condenser.

HUGH J. SCULLEN. 

